Hello
@rower40 - Google's Gemini trawl of all references (it doesn't tell me which ones have been used) has:
The Tonbridge Jubilee railway sidings were named in honour of Queen Victoria’s Golden Jubilee in 1887, when they were originally constructed by the South Eastern Railway to mark the 50th anniversary of her reign.
Only three British monarchs have celebrated the main Jubilees during the railway era - Victoria (silver, gold, diamond), George V (silver) and Elizabeth II (silver, gold, diamond).
Quail identifies the sidings as SER in origin, meaning it would have to be one of Victoria's jubilees: 1862, 1887 or 1897.
NLS maps website has maps identified as Kent L.11, 25", revised 1895, and Kent L.SE, 6", revised 1895, which have no sidings shown. The next one chronologically is Kent L.11, 25", revised 1907, which shows four sidings alongside the down line from Redhill.
So I think Gemini has mis-spoken, and the name celebrates Victoria's
diamond jubilee. Either that or the Ordnance Survey missed their construction by a number of years.